diff --git a/frontend/views/containers/chatroom/file-attachment/ChatAttachmentPreview.vue b/frontend/views/containers/chatroom/file-attachment/ChatAttachmentPreview.vue
index 5735f8803..8435bda84 100644
--- a/frontend/views/containers/chatroom/file-attachment/ChatAttachmentPreview.vue
+++ b/frontend/views/containers/chatroom/file-attachment/ChatAttachmentPreview.vue
@@ -17,7 +17,7 @@
           .c-file-name.has-ellipsis {{ entry.name }}
           .c-file-ext-and-size
             .c-file-ext {{ fileExt(entry) }}
-            .c-file-size(v-if='entry.size') {{ fileSize(entry) }}
+            .c-file-size(v-if='entry.size') {{ fileSizeDisplay(entry) }}
 
       .c-preview-img(v-else)
         img(
@@ -38,7 +38,7 @@
         .c-attachment-actions
           tooltip(
             direction='top'
-            :text='L("Download")'
+            :text='getDownloadTooltipText(entry)'
           )
             button.is-icon-small(
               :aria-label='L("Download")'
@@ -93,9 +93,10 @@
 import sbp from '@sbp/sbp'
 import Tooltip from '@components/Tooltip.vue'
 import { MESSAGE_VARIANTS } from '@model/contracts/shared/constants.js'
-import { getFileExtension, getFileType } from '@view-utils/filters.js'
+import { getFileExtension, getFileType, formatBytesDecimal } from '@view-utils/filters.js'
 import { Secret } from '~/shared/domains/chelonia/Secret.js'
 import { OPEN_MODAL } from '@utils/events.js'
+import { L } from '@common/common.js'
 
 export default {
   name: 'ChatAttachmentPreview',
@@ -156,8 +157,13 @@ export default {
     fileExt ({ name }) {
       return getFileExtension(name, true)
     },
-    fileSize ({ size }) {
-      return size ? `${size} bytes` : ''
+    fileSizeDisplay ({ size }) {
+      return size ? formatBytesDecimal(size) : ''
+    },
+    getDownloadTooltipText ({ size }) {
+      return this.shouldPreviewImages
+        ? `${L('Download ({size})', { size: formatBytesDecimal(size) })}`
+        : L('Download')
     },
     fileType ({ mimeType }) {
       return getFileType(mimeType)
@@ -279,8 +285,14 @@ export default {
 
       .c-file-ext-and-size {
         display: flex;
+        align-items: flex-end;
         flex-direction: row;
-        column-gap: 0.25rem;
+        column-gap: 0.325rem;
+      }
+
+      .c-file-size {
+        color: $text_1;
+        font-size: 0.8em;
       }
     }
 
@@ -314,6 +326,8 @@ export default {
     .is-download-item {
       &:hover .c-attachment-actions-wrapper {
         display: flex;
+        flex-direction: column;
+        align-items: flex-end;
       }
 
       .c-preview-non-image {
diff --git a/frontend/views/utils/filters.js b/frontend/views/utils/filters.js
index f2642435d..4c2d57bb9 100644
--- a/frontend/views/utils/filters.js
+++ b/frontend/views/utils/filters.js
@@ -15,6 +15,17 @@ export const getFileType = (
   return mimeType.match('image/') ? 'image' : 'non-image'
 }
 
+export const formatBytesDecimal = (bytes: number, decimals: number = 2): string => {
+  if (bytes === 0) { return '0 Bytes' }
+
+  const k = 1000 // Decimal base
+  const sizes = ['Bytes', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB']
+  const i = Math.floor(Math.log(bytes) / Math.log(k))
+
+  const formattedValue = parseFloat((bytes / Math.pow(k, i)).toFixed(decimals))
+  return `${formattedValue} ${sizes[i]}`
+}
+
 /**
  * this function filters `list` by `keyword`
  * `list` should be an array of objects and strings